Re: Lamp killing circuit breakers?

Michael Burr <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> Hi all,  this situation is so wierd that I'd appreciate some
> help.  I replaced the dimmer module in my torche halogen floor
> lamp, plugged it in to test, and nothing happened.  I then
> discoverd that all the outlets in my shop area were dead. I went
> to the breaker box and the circuit breaker didn't look tripped,
> but I reset it anyway... still nothing on that branch despite
> multiple resets and unplugging everything.

> Still wanting to test the lamp, I went into the  garage and
> plugged the lamp into an outlet that I know was energized
> because I had just tested it when determining the extent of the
> shop outlets problem.  This time, since I was close to the
> breaker box, I heard the "click" of a breaker being thrown and
> still no light from my lamp.  Back to the breaker box, where the
> circuit breaker for the garage outlets looked fine, but once
> again I reset it anyway... still no power despite multiple
> resets and removing everything else from the circuit.
>
> Both breakers now appear non-functional after simply plugging in
> this innoculous halogen lamp!  Has anybody seen a case where a
> simple appliance has "killed" the circuit breakers?  I'm really
> stumped by this...

    Breakers have to be pushed all the way off and then on again, but it
sounds like you've already tried this.

    You almost certainly have a dead short in your lamp, in either the
wiring or the new module.  Is it possible you may have inadvertantly
connected the wrong wires?

    A short circuit will very often destroy a circuit breaker, especially if
they're old.  The excessive heat and arcing causes parts inside to burn out.
Certain brands are more succeptible to this than others.  Age is also a
factor.  I had a recepticle fall apart and short out at my old home, it
ruined the ancient breaker that fed it.  At my house now the refrigerator
cable got sawed thru while doing some plumbing, the 3mo old SquareD breaker
tripped but was not damaged.

    New breakers are desgined to handle up to a 10,000A (IIRC) fault and
still be usable afterwards, older breakers wern't or may have worn to a
point where they can no longer do so.  Even though your breaker is a "15amp
breaker", in a short-circuit fault situation the actual current will exceed
this, by a lot.  Since the breaker still has to mechanically open the
circuit the current will still flow for a very brief moment while the
contacts get moving, all the while the bi-metal inside is still getting
hotter.  This all may happen in a mere 10th of a second.  The net result
however is that the conductive parts inside your breaker had enough current
flowing through them for that 10th of a second to cause damage.

    You should be thankfull the breakers failed safe (ie: won't re-close yet
no longer offer protection).

-- Steve